Device for projecting pulverulent substances such as fire-extinguishing products or insect-powders



2,926,456 SUCH DERS '9 Ill/111% G. BIRO DEVICE FOR PROJECTINGPULVERULENT SUBSTANCES AS FIRE-EXTINGUISHING PRODUCTS OR INSECT-POWFiled Feb. 3, 1955 March 1, 1960 DEVICE FOR PROJECTING PULVERULENT SUB-STANCES SUCH AS FIRE EXTINGUISHING PRODUCTS OR INSECT POWDERS GuillaumeBiro, Chaville, France Application February 3, 1955, Serial No. 485,958Claims priority, application France February 5, 1954 2 Claims. (Cl.43147) I a A device for projecting a heavy pulverulent product arelatively great distance according to the present invention, comprisesa straight cylindrical ejector tube having a uniform bore of a lengthmaterially greater than the diameter of the bore, the front end portionof the tube being open, a first valve mounted at the rear end of thetube and including a chamber communicating at its front end with theejector tube through a passage of relatively 30 small cross-sectionalarea with respect to the tube bore,

a duct leading from the chamber, asource of supply of the pulverulentproduct comprising a container therefor provided with a low pressure gassupply, the duct connecting the chamber and the container. In thismanner 35 a gaseous stream from the container carrying the pulverulentmaterial in suspension may be led into the chamher, the first valvebeing adapted to adjustably release the gaseous stream and pulverulentmaterial forwardly into the ejector tube. Also provided is a nozzlehaving a throttle disposed axially at an intermediate location along theejector tube and directed forwardly in the ejector tube, means forsupplying gas under relatively high pressure to the nozzle and a secondvalve mounted in the ejector tube adapted to adjust the flow of the highpressure gas into the tube, the two valves being adapted to be adjustedand controlled whereby the pulverulent'material may be projectedfrom theejector tube at a relatively high speed.

The pulverulent product is stored in a tank under a relatively lowpressure which is connected through a fiex- O ible connection to therear portion of the nozzle.

Other objects and features of the invention will appear as the followingdescription proceeds with reference to the attached drawing forming partof this specification and illustrating diagrammatically by way ofexample a 55 preferred form of embodiment of the device.

In the drawing:

Figure l is a longitudinal axial and fragmentary section of the device;

Figure 2 is a cross-section taken upon the line II-Il of Fig. 1;

Figure 3 is a diagrammatical view showing the ejector tube'of the deviceconnected through a first flexible hose to a stationary tank and throughanother flexible hose to a compressedgas cylinder. 65

The device illustrated in Fig. l of the drawing comprises a body 1having formed therein a cylindrical chamher 2 into which leads a duct 3connected to pipe 5. To this inlet pipe 5 is attached a flexible hose 6(see Fig. 3) connected at its other end to the lower portion of areservoir 7 containing a pulverulent product 8 subjected to aired gtatesPatent- ICC the action of a low-pressure gas it). The body 1 of thedevice has mounted 'at its rear portion a handle 12 of a first valve,and having pivotally attached thereon through a pivot pin 13 a hollowand curved actuating lever 15. The curved shape of the upper portion ofthis actuating lever is designed to facilitate the gripping of the leverwith the palm of the hand, the fingers engaging the lower surface of thehandle 12; a spring 16 is interposed between the handle 12 and the leverurging the latter away from the former and against the rear end of thetube 1.

The first valve includes in the front portion of the chamber 2 of body 1a ring 18 secured by three set screws 20 engaging a groove 21 formed inthe ring 18. In the rear portion of the body 1 a sliding rod 22 ismounted co-axially with the chamber 2 and formed with a frusto conical,valve-forming front end 23 adapted to be seated against the rear edge ofthe passage 25 formed with a relatively small cross-sectional area withrespect to the bore of tube 28 in the ring 18 when the sliding rod 22 isallowed to move to the left in chamber 2 (Fig. 1). The rear end portionof the rod 22 extends through a slot 26 formed in the front portion 17of the lever 15 and is formed with a rear annular enlargement 27 of adiameter greater than the width of the slot 26.

The front portion of the body 1 has fitted thereon a cylindrical,straight rigid and relatively large ejector tube.

28. The ejector tube 28 is secured on the body 1 by means of the samescrews 20 employed for securing the ring 18 in the chamber 2. Ejectortube 28 has a uniform bore of a length materially greater than thediameter of the bore and its front end is open.

At an intermediate location along the tube 28 (see Fig. 2) a device foradjustably controlling the inlet of compressed gas is mounted. Thisdevice, a second valve, comprises essentially a body 30 formedintegrally with a handle 31, a needle valve 32, a gas-expanding nozzle33 also formed integrally with the body 30, and a detent 34 adapted tocontrol the needle valve 32. The body 30 is secured on the outer surfaceof the ejector tube 28 intermediate of its ends by means of a pair ofthreaded bolts 35 having screwed thereon blind nuts 36. Nozzle 33projects into the ejector tube 28 through an aperture provided for thispurpose. A suitable gasket surrounding the nozzle 33 is interposedbetween the body 30 and tube 28. A hard-soldering is effected afterassembling the parts to preserve the fluid-tightness of the tube 28. Thenozzle 33 located within the tube 28 is formed with an elbow-likepassage and the outlet throttle 38 of the terminal part of this passageis directed forwardly towards the open end of ejector tube 28.

The stem 40 of the needle-valve 32 is slidably mounted in a socket 41screwed in the body 3%, a suitable sealing gasket being interposedtherebetween. A rubber packing is also provided between the sliding stem49 and the socket 41. The stem 40 is formed externally of the body 39with a head 42 adapted to be lifted wten the lever 34 is actuated; thislever is pivotally mounted on a pivot pin 43 fixed on the handle 31. Acompression spring 45 constantly urges the needle-valve 32 to its seatedposition.

The compressed gas under high pressure enters an inner chamber formed inthe body 36 which contains the-spring 45 through a passage (not shown)provided at its inlet end with a fitting (also not shown) to which isattached one end of a flexible hose 46 (Fig. 3) having its other endattached to the outlet of a compressed-gas cylinder '47.

The operation of the device described hereinabove' is" very simple.The'operator grips the handle 12 and de--' presses the control lever 15of the first valve with the, palm of the hand. The other hand grips thehandle 31 of the second valve controlling the flow of high pressure gasfrom the cylinder 47 and the lever 34 is depressed for this purpose. Atthe same time the outlet of the projection device is pointed toward thearea to be sprayed with pulverulent product.

As the control lever 15 is depressed, the return spring 16 is stressedand the valve stem or rod 22 is pulled to the right (Figs. 1 and 3) asits enlarged portion 27 is engaged by the slotted portion of lever 15.The frustoconical valve 23 is moved into chamber 2 and opensthe axialpassage 25 in ring 18. The low-pressure gas 19 in the reservoir '7escapes through the flexible hose 6 and carries along in suspension astream of pulverulent product particles 8. This stream passes throughthe hose 6, pipe and duct 3 into chamber 2, is expanded a first time asit flows out from the passage 25 of ring 18, then another time at theoutlet of the body 1 as it enters the larger ejector tube 28. Therefore,it circulates throng-h the entire width of the ejector tube 2.3 but at arelatively moderate speed due to the low pressure in the reservoir 7.

- Immediately upon depressing the lever 34, the compressed gas from thecylinder 47 penetrates into the nozzle 33 and is ejected at a relativelyhigh velocity from the throttle 38 forwardly toward the open outlet endof ejector tube 28 as indicated by the arrow F in Fig. l. A suction isthus produced in the rear portion of the ejector tube 2'8 andconsequently the pulverulent product is sucked forwardly. Immediatelyupon clearing the nozzle 33 this product is projected at relatively highspeed in the direction of the ejector tube outlet by the compressed gasexpanding through the throttle 38.

From the foregoing it is apparent that the nozzle device 33 acts as anaccelerator designed to accelerate the flow. of pulverulent product inthe ejector tube 28 and to increase its speed to a substantial extent.The operational range of the device range is therefore very muchincreased. The elastic force of the gas is utilized much moreefficiently than if this gas were fed under a very high pressure to thereservoir 7, because there would be very substantial pressure dropbetween the reservoir 7 and the passage. On the contrary, with thearrangement provided by this invention the reservoir 7 is under arelatively low pressure, i.e. a value :just sufficient to carry alongthe pulverulent product to the body 1. As a result, the pressure drop isvery small. It is the gas fed under a relatively high pressure throughthe nozzle 33 which sucks downwardly the pulverulent productentering thebody and ejector tube 28 projects same without any appreciable pressureloss from the rectilinear ejector tube 28. In other words, theefficiency of the device is improvedwhile reducing the gas consumption.

Moreover, the re-acceleration of the stream of pulverulent product bythe action exerted by the gas expanded in the nozzle 33 will ensure aperfect diffusion of the particles of pulverulent product. In fact,immediately upon clearing the nozzle 33 the solid particles forming thepulverulent product are stirred by the expanded gas and distributeduniformly through the gaseous stream. The stream projected from the tubeoutlet is characterized not only by a very long range but also by aperfect, uniform distribution of solid particles of pulverulent producttherethrough.

Of course, many non-essential constructional details may be altered andmodified in the form of embodiment shown and described herein, withoutdeparting however from the spirit and scope of the invention.

The device according to this invention may be used for projecting anydesired pulverulent'material or products to a relatively remotelocation. Thus, this device may be employed successfully for projectingeither insectpowcier over agricultural areas, or a special anti-freezepowder over a water pool or channel in order to make the water surfacenon-freezing. The gas employed for reeaccelerating and, projecting thepulverulent productmay be of any desired character, such as compressedair or nitrogen.

The device according to this invention is also applicable to theprojection of fire-extinguishing products in pulverulent form in case offire. In this case, of course, the compressed gas will be an inert gas,preferably carbon dioxide, so that the device described and illustratedherein may be employed for carrying out the method described in aco-pending patent application Serial No. 485,959 filed by the applicanton February 3, 1955 for ivfethods of and Devices for Fighting Fireswhich has matured into US. Patent 2,853,139, granted September In fact,this patent relates to a method consisting essentially in projectingonto the seat of a fire a pulverulent product of which each particle iscoated with a layer of frozen carbon dioxide, this coating beingobtained by causing a strong expansion of the carbon dioxide in a nozzlefed with the pulverulent product.

The device of this invention is particularly adapted for implementingthe above-mentioned method by causing the carbon dioxide ot expandthrough the nozzle 33. As already explained in the general descriptionof the operation of the device, the carbon dioxide expanded by the.

nozzle 33 ensures the rte-acceleration of the pulverulent product andthe perfect diffusion of the particles thereof.

However, the strong expansion of the gas, in this case carbon dioxide,causes the latter to freeze around each particle of pulverulent product.Before issuingfrom the bore each particle is thus coated with a layer offrozen carbon dioxide and the particles of pulverulent product are thusprojected onto the seat of the fire. Nevertheless, the freezing of thecarbon dioxide does not occur immediately as it is ejected from thenozzle 33; due to the carbon dioxide impinging against the particles ofpulverulent product, the carbon dioxide will freeze only at somedistance from the nozzle 33, i.e. in the front end portion of theejector tube 28. Therefore, before freezing the carbon dioxide will alsoin this specific case accelerate the stream of pulverulent product topermit the long-range projection thereof as well as the diffusion of theparticles for an optimum dispersion thereof in the blast issuing fromthe device.

What I claim as new is:

l. A device for projecting a heavy pulverulent prodmaterially greaterthan the diameter of said bore, the

front end of said tube being open, a first valve mounted at the rear endof said tube and comprising a chamber communicating at its front endwith said ejector. tube through a passage of relatively smallcross-sectional area with respect to said tube bore and a duct leadingfrom said chamber, a source of supply ofsaid pulverulent productcomprising a container therefor provided with a low pressure gas supply,said duct connecting said chamber and said container, whereby a gaseousstream from said container carrying said pulverulent material insuspension may lead into said chamber, said first valve being adapted toadjustably release said gaseous stream and said pulverulent materialforwardly into said ejector tube, a nozzle having a throttle disposedaxially at an intermediate location along said ejector tube and directedforwardly in said ejector tube, means for supplying gas under arelatively high pressure to said nozzle, and a second valve mounted onsaid ejector tube adapted to adjust the flow of said high-pressure gasinto said tube, said two valves being adapted to be adjusted andcontrolled whereby said pulverulent material may be projected from saidejector tube at a relatively high speed.

2. The device as set forth in claim 1, wherein said chamber is ofcylindrical shape as well as coaxial with said tube, and said duct isdisposed laterally of said chamber.

(References on following page) References Cited in the file of thispatent UNITED STATES PATENTS Schanz June 7, 1938 Bramsen et a1. Apr. 2,1240 Clipson Apr. 18, 1950 Grifiin July 24, 1951 Mueller Jan. 13, 1953 6FOREIGN PATENTS Switzerland Nov. 1, 1927 Switzerland Mar. 16, 1939 GreatBritain July 13, 1949 Great Britain Dec. 31, 1952

